To ask for nub theory guesses?

[Bucdynovehbkfdg]

Hi, had this scan at 13 weeks and really want to know the sex/gender!

I don’t understand nub through at all, but what are your opinions.

I can't see a nub. Instinct says boy but I'm usually wrong.

Hi the nub isn’t visible here, on skull I’m guessing boy but it’s hard to tell

I’ve been thinking I couldn’t see it! But as I said I don’t understand nub theory haha